A common type of metallic convenience closure comprises a panel with an endless score line forming a central removable portion and a peripheral fixed portion that is attached to the cylindrical container. A pull-tab having a nose portion is fastened to the removable portion by a rivet so that when the pull-tab is manually grasped, the nose portion of the pull-tab moves into position adjacent the score line severing the panel. Further movement of the pull-tab completes the severing to remove the removable portion. Typical patents showing such construction are U.S. Pat. Nos. 3,696,961, 3,705,563, 3,819,083 and 3,986,632.
Such closures are effective for the intended purpose but do require various manipulations in the manufacture that increase the cost.
However, they are not 100% safe. If the user of the product in the can moves his hand or finger with a circular motion when in contact with the panel remaining on the can, a cut will occur.
It has also been suggested that a closure be previded which has an opening that is closed by a panel which can be removed or broken as shown, for example, in U.S. Pat. Nos. 3,245,576, 3,274,962, 3,380,622, 3,547,305, 4,253,584 and 3,628,689. A major difficulty with respect to such closures is that the free edge of the metal closure is exposed to the contents and depending upon the contents is a point of incipient corrosion and contamination of the contents.
Accordingly, among the objectives of the present invention are to provide a metal closure which has a panel that can be removed wherein the closure is constructed and arranged to minimize to any tendency for corrosion and resultant contamination of the contents and which is 100% safe.
In accordance with the invention, the metallic closure for a cylindrical container comprises a central panel including means forming a part of the panel for attaching the closure to the end of a container to close the end. The panel has an opening therein and the portion of the metal adjacent the opening is rolled so that the end thereof engages under the inner surface of the panel in a smooth roll such that the free edge is not directly exposed to the contents in the container on which the closure is placed. A composite panel is bonded to the central panel on the outer surface of the central panel.